Our studies are concerned with alterations in brain metabolism that occur during sleep. We have isolated and purified to homogeneity, a phosphoprotein from rat brain which exchanges its phosphates at least foru times more rapidly during sleep than during wakefulness. This phosphoprotein in which the phosphate linkage is to histidine has now been shown to be glucose-6-phosphatase. The increased phosphate turnover on the protein is presumably due to increased enzymatic activity during sleep. We now propose to isolate larger quantities of the enzyme from sheep and cattle brain, and to carry out studies on the kinetics and mechanism of this multifinctional enzyme that would help us to comprehend its role in sleep. We shall also prepare an antibody that could enable us to localize the site of action of this substance in brain, and perhaps to examine its functional effects in the intact animal. Factos S. The sleep promoting substance released into cerebrospinal fluid of sleep deprived goats has now been concentrated and purified from CSF of both goats and humans. The purification will be continued until a homogeneous material is obtained for structural and synthetic chemistry. In the meantime, the partially purified material will be used for physiological studies, especially the electrophysiological effects of Factor S on preoptic, thalamic, and lower brainstem nuclei. Studies of excitatory peptides (Factor E) and other CSF peptides - discovered during purification of Factor S - will continue simultaneously. These studies include final identification of the amino acid and carboh@drate components and determination of sequence. Studies of the effects of Factor E on cortical evoked potentials will be undertaken.